Receiving the WWVB time signal in Portugal (by accident) | Hacker News Reader

Receiving the WWVB time signal in Portugal (by accident)

blog.jgc.org

76 pointsjgrahamc33 comments

I agree with above commenter -- must have been some really exceptional ionosphere conditions or something!

By the way, what's the latest on the retirement/phasing out of these time signal stations? I was under the impression from years ago that they were on the way out / being defunded with some kind of decade-long timescale (in favor of GPS).

> I was under the impression from years ago that they were on the way out / being defunded with some kind of decade-long timescale (in favor of GPS).

There's actually an effort to get more systems in addition to GPS going, as it is a SPoF. eLoran is one option, and has an advantage of actually being in production in other countries already. There are others. The US DoT published a study in January 2021 (PDF):

* https://www.transportation.gov/sites/dot.gov/files/2021-01/F...

So I doubt reducing time signals generally is really on the menu.

There was a 2019 NIST budget proposal to shut down WWV, WWVB, and WWVH, but this was reversed in the final budget. The Wikipedia page has some details. See the last paragraph under "Time signal transmissions", especially the two footnotes.

https://en.wikipedia.org/wiki/WWV_(radio_station)

That said, no one knows what the future holds.

Owners of casio waveceptor watches will be very sad if these stations are ever decommed.

I already am. Random interference will change the time on mine constantly.

I replaced the clock movement on two analog clocks at home to sync with WWVB. It's pretty nice not having to set them up at all, and replacing the battery (not even once a year) is almost fun.

Alternate possibility: Your neighbour was messing with something like this: https://www.instructables.com/WWVB-radio-time-signal-generat...

Just kidding, that's some nice propagation. One of my favourite websites is: https://www.pskreporter.info/pskmap.html

When I want to test an antenna or anything I just call CQ a few times on FT8 and within seconds I get dozens/hundreds of reports and can see how far/what direction my signal is going.

If it's the neighbour I'd be happy to meet them!

The one advantage of this is that my wife told me that she felt bad for the little clock that had been waiting 15 years to receive that signal which gave me the opportunity to get out some of my ham gear and show her.

Pretty easy to generate the WWVB signal, I've written various MSF simulators that look like they'd be easy to tweak to generate WWVB. For reasonably accurate time though you'd want to have something running NTP to drive the simulator. Maybe you've got a time-nut [0] nearby.

[0]http://www.leapsecond.com/time-nuts.htm

Ionosphere conditions are crazy in last months. Maximum usable frequency is very high sometimes. There were successful receptions on 50MHz from Australia to Europe. Even couple of cross atlantic FM band receptions are reported.

Ntp synced emulator for rpi which I use in Australia to sync my citizen skymaster

I didn't write this code. It has about 10-20cm of useful propagation distance (this is a transmitter and may breach local RF regulations)

We're outside the footprint of jjy, wwvb or dcf

https://github.com/hzeller/txtempus

Apparently there's iOS software that can do this. It generates the RF signals using the speakers(!).

Java code does this with coiled headphones. I liked the idea of the pi build out and have it in a cigar box. I ran the Java and it works. It's easy to coil the headphones lead around a watch too.

Dad bought a similar clock few years back in west coast of Lithuania. Apparently it always resets by one hour back which I assume is a time signal from Sweden. No way to disable it so he just lives with it lol.

As far as I know Sweden does not have a time transmitter. My RC controlled watches get their signals from Germany (https://en.wikipedia.org/wiki/DCF77). It follows CET.

I find long distance reception of longwave radio signals (LW DX) fascinating, there are still a few interesting high-power stations that can be heard internationally. The radio is also easy to build - low-noise audio frequency amplifiers and 24-bit ADCs should do. Unfortunately it's extremely impractical for us city dwellers due to the huge antenna required for DXing and the deafening noise from switched-mode or digital devices. It only takes a single bad PSU to trash the LW spectrum.

I'm no antenna expert, but it was my understanding that the WWVB signal could be received on a homecrafted Ferrite Rod antenna.

http://prc68.com/I/Loop.shtml

Antenna of this type are a large ferrite rod, with a number of copper loops forming an effective inductor. With some capacitors, you can filter out other signals (forming a notch at the 60,000 Hz signal to get the WWVB)

Not that I've done this before nor am I any kind of expert on radio. But... its not an especially large antenna from my understanding.

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I can appreciate the issues of noise. The 60,000 Hz signal is a 1-baud (lol) signal, one-bit every second. So you need 60-seconds to transfer the 60-bits of time information to the receiver.

Any noise within that 60 seconds could destroy the signal and make it inaccurate.

A simple ferrite rod antenna is the standard if you're in a covered zone. If you want to pick up distant signals you'll need something better. I've previously heard some amateur radio operators use many meters of random wires around one's backyard, that was what I imagined to be a "large antenna," so I didn't look further. But I just found an ARRL article [0],

> A long wire sometimes works if directly connected to the antenna jack on the transceiver. In reality, a 500 foot long wire is a very short wire (less than 0.1 λ) on 2200 meters. A preferable option is to use a small loop antenna and a preamp. These loops are generally about 2 meters in diameter, and a number of designs can be found on the LF Web sites. Unlike any practical wire antenna an amateur can erect, a loop will not take up much real estate and can be made directional to reduce interference. Once you have your antenna up and can receive commercial longwave stations such as CFH and DCF39, you have sufficient receiver sensitivity and you are now well on your way to receiving amateur signals on LF.

Looks like a small, 2-meter magnetic loop antenna paired with a preamp should work well. Perhaps I should give it a shot one day.

Of course, to transmit a signal (2200 meter is 136 kHz, which is an amateur band), it's a completely different story.

[0] http://www.arrl.org/files/file/Technology/pdf/craig.pdf

Universal Solder in Canada sells just a kit like that.

https://www.universal-solder.ca/product/canaduino-60khz-atom...

For the curious, the National Institute of Standards and Technology (NIST) has a really interesting PDF with the history and technology of WWV, WWVB, and WWVH:

https://tf.nist.gov/general/pdf/1969.pdf

I don't get space weather. A good website might help. Like when the pigeons went missing last month in Portugal possibly from the opposite[1], it's odd there isn't a space weather website to easily check conditions.

Is shortwave more than the k-index? It was low, but not particularly low. Or is it just the opposite that matters.

https://www.foresthillweather.com/SpaceDailyGeomagnetic.php

[1] https://www.portugalresident.com/racing-pigeons-totally-conf...

Sometimes I can’t even get it on the East Coast!

Take a look at NIST's propagation charts for WWVB. You can clearly see the US East Coast getting little signal at certain times during the day: https://www.nist.gov/pml/time-and-frequency-division/radio-s... You're actually getting the best coverage at about the same time my clock was hearing its first signal in 15 years.

Why is the propagation different during different times of day?

On that page, it says

> WWVB radio controlled clocks should be able to work in most places in North America. The red areas on the coverage maps below show where a WWVB radio controlled clock should be able to synchronize. Note that the red area is largest at night, and smallest in the daytime (click on the map to see a larger image). For example, 0600 UTC is about midnight in the central United States.

Why is the propagation different during different times of day?

Welcome to the wonderful world of radio propagation. Different radio signals at different frequencies "bounce around" the world in different ways. LF (low frequency) which is where the WWVB beacon operates bounces off the ionosphere (refracts) and can bounce very long distances.

But the bouncing depends on conditions in the ionosphere which are affected by day/night cycles and sun cycles.

Start here for some information: http://rsgb.org/main/files/2012/10/Understanding_LF_and_HF_p...

I couldn't even get it on the West Coast. When I owned a wristwatch that synced to the time signal, twice a year I'd have to put it in on the windowsill the night of the daylight savings change; otherwise, it never received the signal.

It's kind of miraculous that wristwatches can pick it up at all given how little space they can dedicate to an antenna. I live at the very outer Northwestern edge of WWVB's coverage, in the Seattle area, and my similarly equipped wristwatch reliably gets the signal -- but only at night, and, curiously, only if I'm wearing it! My theory, which I've never done any research on, is that the conductive metal backing of the watch allows some of my own body to serve as an antenna.

I'm in the same boat - my WWVB wristwatch needs a nightly spot near a window to make it work

That is really cool. I wonder if there were any extraordinary atmospheric conditions going on.

This appears to be JGC's first post since 2010. Perhaps the Cloudflare IPO has finally enabled him to take a holiday! Well done, John!

You're looking at the "popular posts" section at the bottom of the page, not a list of all articles.

What makes you say that? I've posted lots of things. Such as this: https://blog.jgc.org/2021/04/aeronear-ambient-device-showing...

Whoops!

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